5aPP20. Toward a model for clinical evaluation of hearing loss and hearing
aids using articulation index.

Routine clinical application of the articulation index (AI) has been
reported previously [A. R. Thornton et al., ASHA 34, 148 (1992); Z. Hou et al.,
ASHA 35, 234 (1993); Z. Hou and A. R. Thornton, Ear Hear. 15(2) (1994)]. This
paper reports further development of an AI-based clinical model for evaluating
hearing loss and hearing aids and for maximizing hearing aid performance across
listening conditions. AIs across a range of listening conditions are plotted on
a series of two-dimensional graphs to provide visual evaluations of a patient's
residual speech ability under each condition with or without a hearing aid. The
AIs are integrated to obtain an integrated articulation index (IAI) as a
criterion measure for evaluating the overall speech ability across the
conditions. The optimal IAI is suggested as a hearing aid prescription method.
An audibility improvement index based on the IAI is introduced to evaluate the
benefit a patient might gain from using a hearing aid. This model can address
loss and amplification requirements in both quiet and noise conditions and
provides a comprehensive and easy-to-use tool for routine clinic applications.